Tom basically stops replying when he's shown to be wrong. In the "clouds lit from below" thread Tom claimed that perspective causes the effect (he claimed that If I raise my hand so it looks like it is above a distant light then the shadow is cast upwards). I did an experiment to prove him wrong, posted photographic evidence. No response. I subsequently drew this diagram to say how ridiculous his claim was:

There is no way to cling to flat earth theory without invoking conspiracy. NASA, every other space agency, the airline industry, the cruise line industry, the satellite TV industry, the GPS industry.
A LOT of people would have to be "in on it". And why? Why is the "fact" that the earth is flat such a terrible truth which must be hidden from us. I know the answer to some of that are that "NASA think it's a sphere so their CGI images show it that way" but it's still a conspiracy because they are hiding the truth that they can't go into space, as are some of the other people I mentioned.
Their Occam's Razor page says:
"What's the simplest explanation; that NASA has successfully designed and invented never before seen rocket technologies from scratch which can accelerate 100 tons of matter straight up at 7 miles per second, and that NASA can do the impossible on a daily basis, explore the solar system, and constantly wow the nation by landing a man on the moon and sending robots to mars; or is the simplest explanation that they really can't do all of that stuff?"
I would counter that by saying something like:
"What's the simplest explanation; that NASA, every other space agency, the people who run GPS, satellite TV, weather and communication satellites, the airline and cruise line industry who plot their routes based on a spherical earth...is it simpler to think that they are all lying to us to us for reasons which are not well explained and that all of science is wrong; or is the simplest explanation that the earth is indeed spherical?"